|Peterson Munks, Brekke|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/15/2016
Publication Date: 11/6/2016
Citation: Peterson-Munks, B.L., Steiner, J.L. 2016. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures [abstract]. ASA-CSSA-SSSA Annual Meeting, Resilience Emerging from Scarcity and Abundance, November 6-9, 2016, Phoenix, Arizona. Available: https://scisoc.confex.com/scisoc/2016am/webprogram/Paper101348.html.
Interpretive Summary: Abstract only.
Technical Abstract: Previous research indicates that a difference occurs in native and non-native grass species in regard to drivers of greenhouse gas (GHG, (carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O))) emissions from soil. Drivers of soil nutrients could help establish best management practices to mitigate GHGs and store soil C and N. We hypothesized that the magnitude of labile soil carbon (C) and nitrogen (N) would increase with soil moisture followed by an increase in GHG emissions in non-native grass pasture soils early in the growing season compared to native grass pasture soils. A study at the USDA-ARS Grazinglands Research Laboratory, El Reno, OK was conducted in to: 1) determine seasonal soil C and N content and 2) to obtain seasonal GHG emissions of soils under native and non-native perennial grasses. Bi-weekly sampling of soil GHG and water content (0-15cm) occurred in both pasture types in replicates of five. Greenhouse gas samples were analyzed for CO2, CH4 and N2O on a gas chromatograph. Soil water content (SWC) and physical properties and labile C and N were determined using standard methods. Initial results indicate that in native grass pastures the magnitude of CO2 and N2O were proportional to SWC, and that CH4 assimilation decreased in response to SWC compared to soils under non-native grasses. Soils under non-native grasses exhibited increased magnitudes of CO2 and N2O, while CH4 assimilation was similar to that observed in soil under native grasses during warmer seasonal trends where moisture was limited. The implication of this research indicates that GHG fluxes from soils in semi-arid environments are altered by abiotic drivers and assimilate CH4.